The invention relates to a dual flow or double-flow hard-soldered or brazed flat tube evaporator for a motor vehicle air conditioning equipment with one row in the air flow direction, the evaporator being made of aluminum or an aluminum alloy and having the features of the preamble of claim 1. Such a double-flow flat tube evaporator is known from the DE-195 15 526 C1 among further embodiments with more than two flows.
Commercially available flat tube evaporators of such a construction have a structural depth of 60 mm in prototypes which just have become public, while the standard structural depth in comparable plate evaporators is 66 to 100 mm.
As the mentioned publication, according to which the preamble of claim 1 is formed, already shows, in the past efforts have been made to increase the efficiency going over to evaporators with more than two flows, if desired.
Moreover, in double-flow evaporators as well as in evaporators having more than two flows, efforts have been made to feed the individual flat tubes in a proportion of liquid to gaseous refrigerant which is as constant as possible, and for this purpose to distribute the refrigerant to the inlets of groups of flat tubes on the inlet side, as it is already provided in the mentioned kind of evaporators, according to which the preamble of claim 1 is formed. In equivalence thereto, the idea to carry out this distribution furthermore with respect to each individual flat tube, which idea is at present not traceable in the prior art, is considered to be included in the kind of evaporators referred to in the preamble of claim 1. Such a distribution to individual tubes of an evaporator, but not expressively of a flat tube evaporator, is known per se from the EP-A1-0 566 899.
In all such distributions of the refrigerant to flat tubes on the inlet side, at the same time a distribution to all chambers of the respective flat tube is effected, which chambers extend one after the other in the direction of the structural depth of the evaporator. In this case, the structural depth of the evaporator is identical to the corresponding breadth dimension of the flat tube in a borderline case. The breadth dimension of the flat tube, however, can also be somewhat smaller, in particular if a corresponding overhang of the zig zag fins is included on a front side.
The fitting space available in the motor vehicle is always a main problem, in particular when fitting structural members into motor vehicles. Therefore, with structural members to be fitted into motor vehicles, there generally always is a tendency to minimize the outer dimensions with a useful effect being predetermined. It has to be taken as granted that this basic idea was also the basis in all known generic flat tube evaporators referred to in the preamble of claim 1 which are on the market. One can derive from this fact that the experts did not consider a structural depth of less than 60 mm to be appropriate in such flat tube evaporators, taking into consideration all requirements.